This image from Oxford University Press shows the cover of â€The Yellow Book: CDC Health Information for International Travel, 2014.â€ The book offers up-to-date advice and recommendations from the U.S. Centers for Disease Control on staying healthy around the world, including recommendations for vaccines, disease prevention and coping with common problems like diarrhea, jet lag, insect bites, sunburn and altitude sickness. (AP Photo/Oxford University Press)

“As of July 18, 2013, CDC has been notified of more than 200 cases of cyclospora infection in residents of multiple states, including Iowa, Nebraska, Texas, and Wisconsin,” the FDA said in a statement.

The agency said it is unclear whether all the cases are part of the same outbreak.

Cyclosporiasis is caused by ingesting food or water containing a one-celled parasite that is too small to be detected without a microscope. Symptoms include watery diarrhea, vomiting and body ache.

Untreated, the illness can last from a few days to a month or more. Other symptoms may include headache, fever, weight loss and fatigue.

Most people with healthy immune systems recover from the infection without treatment. Older people and those with weakened immune systems might be at higher risk for prolonged illness. The condition is typically treated with the antibiotics Bactrim, Septra and Cotrim, according to the CDC.

Cyclosporiasis is most common in tropical and subtropical regions of the world. Outbreaks in the United States and Canada have been linked to imported fresh produce.